Any long term or short term problems with running 1 catalytic converter on one bank and the other bank doesn’t have one on a Y-pipe setup exhaust

[618 Syndicate]

I don't know where this info is coming from but I don't believe it's accurate. The '99-'00 "classic" GMT400s should have the same black box PCM and harness as a '98. The GMT800s all got 0411s or similar.

This.

 

[618 Syndicate]

I think the catch is with my suburban being a 99 model gmt400 they may have gave that extra Obs year the 99-02 NBS connector design and box even tho it’s gmt 400

Nope.

 

[A97obs]

Nope.

I’m telling you straight forward I pulled a matching service No.16263694 black box from a 99 NBS 4.3L silverado today that’s the same Box externally visually as my 99’ suburban the connectors are gray on the nbs box that’s the difference and the wiring looms out of the connectors on the left side “toward the core support side of the connectors because the nbs trucks place the box down off the driver side fender toward the core support. Which you probably know already just sayin..
My black connector wires Angle to the firewall !

I’ve already plugged the box into my suburbans connectors . Yes some of the pin outs on the connectors are diff to be expected but the plugs them selves plug into a 99’ 5.7 and my connector pins would already be pinned where they need to be .

I also Yanked the core support tag when I took the pcm form the 99.

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[A97obs]

This.

No bs i don’t know where someone’s info is coming from but there was a 99 and 2000 year NBS in front of me / I pulled the plastic cover off both of them exposed 2 black boxes with the same service number. I just chose to take the 99 4.3L box
I also seen plenty of other 99 to 2002 boxes that were in NBS trucks that were not the desired 0411 service numbers they were another different code but physically identical as the 0411.

I even bought a 3rd 2002 Chevy Astro AWD 0411 box at the same point that I randomly ran across .. they were about to crush the vehicle .

 

[fancyTBI]

Why can’t you just use the existing one from the truck that has these converter issues? You are making this way more difficult than it needs to be.

Pick one of the two following:

1) Replace the Y pipe with a new one, drive.

2) replace the converters with new exhaust pipe, get a tune for the O2 sensors, drive.

If you’re planning on doing a lot more engine modifications, yeah the 0411 is probably a good option. If you want to just tune out the O2, use what you have already.

It doesn’t help that your posts are hard to follow man. I think having some clearer responses would help everyone and most importantly, help you!

 

[618 Syndicate]

It's possible the early V6 trucks had the black box still, but the 02 V6 NBS I owned was definitely not a black box ECM.

 

[fancyTBI]

It's possible the early V6 trucks had the black box still, but the 02 V6 NBS I owned was definitely not a black box ECM.

I was just thinking this. V6 didn’t change a whole lot to my knowledge so they could probably save some costs by avoiding converting to the 0411 early on.

 

[df2x4]

Why can’t you just use the existing one from the truck that has these converter issues? You are making this way more difficult than it needs to be.

X2.

If you're disabling the rear O2 sensors in the tune yourself using HPTuners or similar then step one is to back up your existing stock tune to a file on the computer. That way if you ever want to go back to stock you can just re-flash that file to the PCM. This is a 5-10 minute job and easier than physically swapping the PCMs IMO. The only reason for an extra PCM would be if you're having it tuned by someone else and don't have access to the software.

 

[A97obs]

Why can’t you just use the existing one from the truck that has these converter issues? You are making this way more difficult than it needs to be.

Pick one of the two following:

1) Replace the Y pipe with a new one, drive.

2) replace the converters with new exhaust pipe, get a tune for the O2 sensors, drive.

If you’re planning on doing a lot more engine modifications, yeah the 0411 is probably a good option. If you want to just tune out the O2, use what you have already.

It doesn’t help that your posts are hard to follow man. I think having some clearer responses would help everyone and most importantly, help you!

Why because I drive this truck daily ! I need to retain a working PCM unit .
My entire post on why I was getting a donor box to tune was just answered . Thanks for letting me elaborate on why if it seems completely complex . It really isn’t , I’m getting mixed replies info knowledge from all angles and none of it is worthy of just agreeing .

I have 2-3 diff tune guys experts hang around just saying this works that works so I’ mean I’m out spending $ doing my leg work to get a tune done and I can’t proceed if I can’t willingly get sound advice or 100% correct info .

 

[A97obs]

X2.

If you're disabling the rear O2 sensors in the tune yourself using HPTuners or similar then step one is to back up your existing stock tune to a file on the computer. That way if you ever want to go back to stock you can just re-flash that file to the PCM. This is a 5-10 minute job and easier than physically swapping the PCMs IMO. The only reason for an extra PCM would be if you're having it tuned by someone else and don't have access to the software.

Yes you nailed it , I have no knowledge and never have tune, but I’m at this point ready to learn myself. My box was being sent out to somebody to be tuned. Yes, that is why I needed to keep my box in my truck to drive to work yes, in the meanwhile, collecting all the cat converters and components to fix my exhaust you nailed it !!

I already thought about asking whoever is going to tune it to send me the back up file. .. or hence keeping my stock pcm stock and using the donor so when I swap to off road pipe and every other change I immediately have an already tuned PCM to plug and play